Structure-from-motion (SFM) refers to the recovery of 3D-shape or depth structure from the 2D-velocity pattern of a moving object or scene falling on the retina. The psychophysics of this phenomena has been extensively studied either for objects undergoing rotations about an axis in the frontoparallel plane (i.e., perpendicular to the line of sight) or translational motion. However, there is a lack of research regarding human performance in SFM recovery for rotational motion about an arbitrary axis. In this proposal the ability to recover SFM in humans when the axis of rotation is not in the frontoparallel plane will be assessed using psychophysical techniques. It will also be studied how binocular disparity, when also present, interacts with motion in the recovery of the depth structure. All this experimental data will be used as a base for extending an existing physiologically based model of SFM computation to this general case of an arbitrary axis of rotation. Knowing how the visual system computes SFM is not only essential for understanding the brain per se, but also important for finding psychophysical diagnostic tools for pinpointing potential areas of brain damage.